add test checking that we don't accidentally expose const-unstable in…

…trinsics

tests/ui/consts/auxiliary/unstable_intrinsic.rs

@@ -0,0 +1,26 @@
+#![feature(staged_api, rustc_attrs, intrinsics)]
+#![stable(since="1.0.0", feature = "stable")]
+
+#[stable(since="1.0.0", feature = "stable")]
+pub mod old_way {
+    extern "rust-intrinsic" {
+        #[unstable(feature = "unstable", issue = "42")]
+        pub fn size_of_val<T>(x: *const T) -> usize;
+
+        #[unstable(feature = "unstable", issue = "42")]
+        #[rustc_const_unstable(feature = "unstable", issue = "42")]
+        pub fn min_align_of_val<T>(x: *const T) -> usize;
+    }
+}
+
+#[stable(since="1.0.0", feature = "stable")]
+pub mod new_way {
+    #[unstable(feature = "unstable", issue = "42")]
+    #[rustc_intrinsic]
+    pub const unsafe fn size_of_val<T>(x: *const T) -> usize { 42 }
+
+    #[unstable(feature = "unstable", issue = "42")]
+    #[rustc_const_unstable(feature = "unstable", issue = "42")]
+    #[rustc_intrinsic]
+    pub const unsafe fn min_align_of_val<T>(x: *const T) -> usize { 42 }
+}

tests/ui/consts/const-unstable-intrinsic.rs

@@ -0,0 +1,66 @@
+//! Ensure that unstable intrinsics can actually not be called,
+//! neither within a crate nor cross-crate.
+//@ aux-build:unstable_intrinsic.rs
+#![feature(staged_api, rustc_attrs, intrinsics)]
+#![stable(since="1.0.0", feature = "stable")]
+#![feature(local)]
+
+extern crate unstable_intrinsic;
+
+fn main() {
+    const_main();
+}
+
+const fn const_main() {
+    let x = 42;
+    unsafe {
+        unstable_intrinsic::old_way::size_of_val(&x);
+        //~^ERROR: unstable library feature 'unstable'
+        //~|ERROR: cannot call non-const fn
+        unstable_intrinsic::old_way::min_align_of_val(&x);
+        //~^ERROR: unstable library feature 'unstable'
+        //~|ERROR: not yet stable as a const fn
+        //~|ERROR: cannot use `#[feature(unstable)]`
+        unstable_intrinsic::new_way::size_of_val(&x);
+        //~^ERROR: unstable library feature 'unstable'
+        //~|ERROR: not yet stable as a const fn
+        //~|ERROR: cannot use `#[feature(unstable)]`
+        unstable_intrinsic::new_way::min_align_of_val(&x);
+        //~^ERROR: unstable library feature 'unstable'
+        //~|ERROR: not yet stable as a const fn
+        //~|ERROR: cannot use `#[feature(unstable)]`
+
+        old_way::size_of_val(&x);
+        //~^ERROR: cannot call non-const fn
+        old_way::min_align_of_val(&x);
+        //~^ERROR: cannot use `#[feature(local)]`
+        new_way::size_of_val(&x);
+        //~^ERROR: cannot use `#[feature(local)]`
+        new_way::min_align_of_val(&x);
+        //~^ERROR: cannot use `#[feature(local)]`
+    }
+}
+
+#[stable(since="1.0.0", feature = "stable")]
+pub mod old_way {
+    extern "rust-intrinsic" {
+        #[unstable(feature = "local", issue = "42")]
+        pub fn size_of_val<T>(x: *const T) -> usize;
+
+        #[unstable(feature = "local", issue = "42")]
+        #[rustc_const_unstable(feature = "local", issue = "42")]
+        pub fn min_align_of_val<T>(x: *const T) -> usize;
+    }
+}
+
+#[stable(since="1.0.0", feature = "stable")]
+pub mod new_way {
+    #[unstable(feature = "local", issue = "42")]
+    #[rustc_intrinsic]
+    pub const unsafe fn size_of_val<T>(x: *const T) -> usize { 42 }
+
+    #[unstable(feature = "local", issue = "42")]
+    #[rustc_const_unstable(feature = "local", issue = "42")]
+    #[rustc_intrinsic]
+    pub const unsafe fn min_align_of_val<T>(x: *const T) -> usize { 42 }
+}

tests/ui/consts/const-unstable-intrinsic.stderr

@@ -0,0 +1,186 @@
+error[E0658]: use of unstable library feature 'unstable'
+  --> $DIR/const-unstable-intrinsic.rs:17:9
+   |
+LL |         unstable_intrinsic::old_way::size_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #42 <https://github.com/rust-lang/rust/issues/42> for more information
+   = help: add `#![feature(unstable)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable library feature 'unstable'
+  --> $DIR/const-unstable-intrinsic.rs:20:9
+   |
+LL |         unstable_intrinsic::old_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #42 <https://github.com/rust-lang/rust/issues/42> for more information
+   = help: add `#![feature(unstable)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable library feature 'unstable'
+  --> $DIR/const-unstable-intrinsic.rs:24:9
+   |
+LL |         unstable_intrinsic::new_way::size_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #42 <https://github.com/rust-lang/rust/issues/42> for more information
+   = help: add `#![feature(unstable)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable library feature 'unstable'
+  --> $DIR/const-unstable-intrinsic.rs:28:9
+   |
+LL |         unstable_intrinsic::new_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #42 <https://github.com/rust-lang/rust/issues/42> for more information
+   = help: add `#![feature(unstable)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0015]: cannot call non-const fn `unstable_intrinsic::old_way::size_of_val::<i32>` in constant functions
+  --> $DIR/const-unstable-intrinsic.rs:17:9
+   |
+LL |         unstable_intrinsic::old_way::size_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+
+error: const function that might be (indirectly) exposed to stable cannot use `#[feature(unstable)]`
+  --> $DIR/const-unstable-intrinsic.rs:20:9
+   |
+LL |         unstable_intrinsic::old_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this what you probably want to do)
+   |
+LL + #[rustc_const_unstable(feature = "...", issue = "...")]
+LL | const fn const_main() {
+   |
+help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
+   |
+LL + #[rustc_allow_const_fn_unstable(unstable)]
+LL | const fn const_main() {
+   |
+
+error: `unstable_intrinsic::old_way::min_align_of_val` is not yet stable as a const fn
+  --> $DIR/const-unstable-intrinsic.rs:20:9
+   |
+LL |         unstable_intrinsic::old_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add `#![feature(unstable)]` to the crate attributes to enable
+
+error: const function that might be (indirectly) exposed to stable cannot use `#[feature(unstable)]`
+  --> $DIR/const-unstable-intrinsic.rs:24:9
+   |
+LL |         unstable_intrinsic::new_way::size_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this what you probably want to do)
+   |
+LL + #[rustc_const_unstable(feature = "...", issue = "...")]
+LL | const fn const_main() {
+   |
+help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
+   |
+LL + #[rustc_allow_const_fn_unstable(unstable)]
+LL | const fn const_main() {
+   |
+
+error: `unstable_intrinsic::new_way::size_of_val` is not yet stable as a const fn
+  --> $DIR/const-unstable-intrinsic.rs:24:9
+   |
+LL |         unstable_intrinsic::new_way::size_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add `#![feature(unstable)]` to the crate attributes to enable
+
+error: const function that might be (indirectly) exposed to stable cannot use `#[feature(unstable)]`
+  --> $DIR/const-unstable-intrinsic.rs:28:9
+   |
+LL |         unstable_intrinsic::new_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this what you probably want to do)
+   |
+LL + #[rustc_const_unstable(feature = "...", issue = "...")]
+LL | const fn const_main() {
+   |
+help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
+   |
+LL + #[rustc_allow_const_fn_unstable(unstable)]
+LL | const fn const_main() {
+   |
+
+error: `unstable_intrinsic::new_way::min_align_of_val` is not yet stable as a const fn
+  --> $DIR/const-unstable-intrinsic.rs:28:9
+   |
+LL |         unstable_intrinsic::new_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add `#![feature(unstable)]` to the crate attributes to enable
+
+error[E0015]: cannot call non-const fn `old_way::size_of_val::<i32>` in constant functions
+  --> $DIR/const-unstable-intrinsic.rs:33:9
+   |
+LL |         old_way::size_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+
+error: const function that might be (indirectly) exposed to stable cannot use `#[feature(local)]`
+  --> $DIR/const-unstable-intrinsic.rs:35:9
+   |
+LL |         old_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this what you probably want to do)
+   |
+LL + #[rustc_const_unstable(feature = "...", issue = "...")]
+LL | const fn const_main() {
+   |
+help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
+   |
+LL + #[rustc_allow_const_fn_unstable(local)]
+LL | const fn const_main() {
+   |
+
+error: const function that might be (indirectly) exposed to stable cannot use `#[feature(local)]`
+  --> $DIR/const-unstable-intrinsic.rs:37:9
+   |
+LL |         new_way::size_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this what you probably want to do)
+   |
+LL + #[rustc_const_unstable(feature = "...", issue = "...")]
+LL | const fn const_main() {
+   |
+help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
+   |
+LL + #[rustc_allow_const_fn_unstable(local)]
+LL | const fn const_main() {
+   |
+
+error: const function that might be (indirectly) exposed to stable cannot use `#[feature(local)]`
+  --> $DIR/const-unstable-intrinsic.rs:39:9
+   |
+LL |         new_way::min_align_of_val(&x);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: if the function is not (yet) meant to be exposed to stable, add `#[rustc_const_unstable]` (this what you probably want to do)
+   |
+LL + #[rustc_const_unstable(feature = "...", issue = "...")]
+LL | const fn const_main() {
+   |
+help: otherwise, as a last resort `#[rustc_allow_const_fn_unstable]` can be used to bypass stability checks (this requires team approval)
+   |
+LL + #[rustc_allow_const_fn_unstable(local)]
+LL | const fn const_main() {
+   |
+
+error: aborting due to 15 previous errors
+
+Some errors have detailed explanations: E0015, E0658.
+For more information about an error, try `rustc --explain E0015`.